Household refrigerator



Dec. 29, 1953 c. F. ALSING 3,9

HOUSEHOLD REFRIGERATOR Filed Feb. 18, 1952 5 Sheets-Sheet l go 1 y 35.-D I 37- t i I N V EN TOR. Carl 1452'] B Y WX M Dec. 29, 1953 c. F.ALSING HOUSEHOLD REFRIGERATOR 3 Sheets-Sheet 2 Filed. Feb. 18, 1952 m T.N 1 IV W Carl F 14151739 BY MM 42 50; rzqy Dec. 29, 1953 c. F. ALSINGHOUSEHOLD REFRIGERATOR I5 Sheets-Sheet 3 Filed Feb. 18, 1952 Dzlsc/zar 6Line INVENTOR. Carl 1 /115215) Ice flrealrz dwzparflrzelzi :EEEEEiEcPatented Dec. 29, 1953 HOUSEHOLD REFRIGERATOR Carl F. Alsing,Evansville, Ind; assignor to Seeger Refrigerator Company, St. Paul,Mimn, a corporation of Mlnneso Application February 18, 1952, Serial No.272,056

13 Claims. (Cl. 62-11735) The present invention relates to householdrefrigerators, and is particularly concerned with householdrefrigerators of the type utilizing an evaporator enclosure for freezingice cubes and for storage of frozen food, and utilizing the exterior ofthe evaporator enclosure for cooling a higher temperature food storagespace.

One of the difllculties encountered in the cooling of a food storagespace by means of a freezing evaporator lies in the fact that theambient temperature under which the household refrigerator operates mayvary greatly. The operation of the motor compressor is controlled by athermostatic switch which is responsive to temperature conditions atsome part of the evaporator. If the size of the evaporator and coolingarea for the food storage space are properly proportioned for hightemperature ambients, it is found that the food storage space willbecome too cold under the low temperature ambients.

One of the objects of the present invention is the provision of animproved refrigeration system in which the amount of effective coolingarea of the evaporator which is available for cooling the food storagespace is automatically varied by the operation of the system in suchmanner that the freezing en losure of the evaporator is always kept at al w temperature below freezing; but the food stoiage space is alwayskept at a suitable temperature above freezing, even though the ambienttemperature under which the household refrigerator operates may varygreatly, as it does, when the same refrigerator is intended to be usedin extremely cold climates and extremely hot climates.

Another object of the invention is the provision of an improvedhousehold refrigerator utilizing an evaporator enclosure for freezingice and storing frozen food, and utilizing the exterior of theevaporator enclosure for cooling the food storage space, in which thefrozen food space is always maintained at a suitable temperature belowfreezing, while the food storage space is always maintained at asuitable temperature above freezing, without the necessity for employingany complicated controls other than a simple thermostatic switch for thecompressor circuit, which is operated responsive to the temperature ofsome part of the evaporator.

Another object of the invention is the provision of an improvedrefrigeration system which takes advantage of the characteristic of oilof absorbing different amounts of refrigerant, such as Freon, dependingupon the temperature and pressure of the mineral oil which is employedfor this 2 purpose and for lubricating the compressor, to reduce theeffective amount of refrigerant available under different ambienttemperatures. The refrigerant employed, commercially known as Freon orF12, is technically known as dichlorodifluormethane.

Another object of the invention is the provision of an improvedhousehold refrigerator, the evaporator of which is provided with asupercold ice cream compartment which is always maintained at atemperature suitable for the storage of ice cream in preference torefrigerating the other parts of the evaporator or the food storagespace, which is external to the evaporator.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews. I

Referring to the drawings, of which there are three sheets,

Fig. 1 is a front elevational view of a household refrigerator embodyingthe invention, shown with its door open;

Fig. 2 is a fragmentary side elevational view, taken on the plane of theline 22 of Fig. 1, looking in the direction of the arrows, with the doorclosed;

Fig. 3 is a view in perspective of an improved form of evaporatorprovided with a special ice cream compartment;

Fig. 4 is a sectional view showing another form of evaporator withoutthe ice cream compartment;

Fig. 5 is a diagrammatic view showing the refrigeration system which isemployed.

The present household refrigerator preferably includes a cabinet havingan outer metal shell l0 and an inner metal liner II spaced from eachother} land insulated by means of suitable insulalOIl The shell l0 andliner II are joined about the door opening by a suitable breaker strip13; and the front opening is closed by a door [4, comprising an outermetal door shell I5, an inner door panel [6, joined together at theupper inner corner H, where the door carries a suitable seal I8,engaging the face of the cabinet shell l0 around the door opening.

The insulating door panel It may be provided with a suitable depressionis for receiving the door shelves 20 and the space between the inner andouter panel and shell of the door is filled with a suitable insulation2|. The inside space in the liner'is divided into a lower food storageaeeaace space 22 and an upper evaporator housing space 23 by a suitablemolded plastic drawer 24, which is slidably mounted upon guides carriedby the liner walls, and which serves as a storage space at a temperatureintermediate between that inside the evaporator and that which ispresent in the food storage space 22.

The guides 25 for the plastic drawer 24 have air circulation passagesthrough them so that the air may circulate upward along both of the sidewalls 26, 21 of the liner ID. The guides 25 also support integraltrunnions 28 carried by the pivotally mounted evaporator door 29, whichmay swing from an upper vertical position to a lower vertical positionso that it can never be damaged by closing of the door.

The sliding drawer 24 is spaced from the back wall 30 of the liner,leaving an air circulation space at 3| for the circulation of airpassing from the food storage space 22 to the space 23 around theevaporator.

In a similar manner the front edge of the sliding drawer 24 is spacedfrom the door, leaving an air circulation space 32; and the door shelves2!) may have through holes or an air circulation space at 33 between theshelves and the inner door panel 16.

In the lower part of the food storage space 22 there may be provided amolded plastic sliding drawer 34 slidably mounted upon guides 35 carriedby the liner walls 26 and 21 and covered with a glass cover 36 carriedby said guides. The guides 35 again have air circulation apertures forpermitting the air to circulate down into the space 31 surrounding thesliding drawer 34; and the glass cover 36 may terminate short of theback wall 30 of the liner and short of the inner door panel IQ for aircirculation.

A plurality of wire shelves 38, 39, 40 may be adjustably mounted on theside walls 26 and 21 by having their front and back wire frame members4| project laterally into rubber or plastic grommets 42 mounted inapertures in the side walls 26, 21 of the liner.

The cabinet is cooled by a suitable evaporator 43, which may besupported from. the front part of the top wall 44 of the liner by anglebrackets 45 and from the rear wall 30 of the liner by angle brackets 46.

The evaporator 43 may be either of the types shown in Figs. 3 or 4. Forexample, the evaporator of Fig. 3 comprises a substantially U-shapedsheet metal member 41 having a vertical side wall 48, a horizontalbottom 49, and a vertical side wall 53, these walls being joined by easybends 59 and being made of suitable metal, such as sheet aluminum.

The side walls 48 and 50 carry a horizontal shelf 5|, comprising arectangular sheet metal aluminum member having downwardly extendingattaching flanges 52 which are riveted to the side walls 48 and 50; andthe back of the evaporator is closed by means of a rectangular sheetmetal back wall 53 of aluminum, which extends from the bottom to the topof the evaporator and issecured by having attaching flanges 54 rivetedto the side walls.

The top of the evaporator is closed by engagement of its upper edgeswith the top wall 44 of the liner; and the front of the evaporator isclosed by means of the plastic door 29 rotatably supported upon itstrunnions 28 on the guides 25.

A vertical partition 55 is located close to the side wall 50 to form arectangular ice cream compartment; and this partition may be riveted tothe horizontal shelf 5| by means of an attaching flange 56 and to thebottom 49 by means of an attaching flange 51'.

The shelf 5! is preferably spaced from the upper edges of the evaporatorby an amount suitable to permit the insertion of ice trays of any depthwhich may be used, or the spacing may be made suitable to receive frozenfood packages, in addition to the ice trays.

The evaporator is preferably provided on one of the walls with arefrigerant receiver or boiler 60, comprising a tubularmetal member ofaluminum, which is substantially cylindrical, but which has both of itstapered end portions 61 and 62 spun into a tapered or rounded smallertubular formation. These end portions serve as inlets and outlets forthe boiler, which is primarily intended to separate the liquid from thevapor, and which preferably has its suction outlet 63 extending in thetubular end portion 6i and turned upward, as indicated at 64.

The inlet tube 65 extends into the opposite end portion 62 anddischarges mixed vapor and liquid under certain conditions into thereceiver 60. Due to the upwardly turned end 64 at the outlet, only vaporis drawn from the receiver by the pump, the liquid accumulating on thebottom portion of the receiver 60.

The receiver 50 is preferably supported in an elongated aperture 66 inthe wall and has integral attaching fins 61 above and below thereceiver, which are riveted to the wall, with the receiver projectingthrough the aperture 66, but having its major portion on the outside ofthe aperture 66.

In the evaporator of Fig. 3, indicated at 43. the receiver is preferablyplaced on the back wall 53; and the evaporator is provided with sinuousaluminum cooling coils which are welded to the bottom of the shelf andto the sides and bottom of the evaporator for intimate heat conductingcontact with these parts. The sinuous coils are preferably arranged asfollows:

The inlet to the evaporator coils from the capillary tube as indicatedat 68, at the right rear wall corner. The tubes are then arrangedsinuously on the right wall 53, covering that portion of the right walland the bottom 49, which forms a part of the ice cream compartment 69.Thus the sinuous coils 10 extend downward across the right side of theice cream compartment 69 and under the ice cream compartment, where theyare bent backwardly across the bottom and up the side again in regularsinuous portions, as shown, to cover the side and bottom of the icecream compartment. The last upwardly extending tubular portion H on theicecream compartment wall passes through the wall and extends backwardlyon the bottom of the shelf 51 and is formed into sinuous portions 12,extending back and forth under the shelf, and cooling the top of the icecream compartment 69.

From the top of the ice cream compartment the coils extend backwardly at13 under the shelf and are brought to the left, with a portion 14extending over adjacent the left wall 48. The frozen food compartment 15is located below this portion of the shelf 51; and the shelf is providedwith laterally extending sinuous portions 16 covering it from front toback on its lower side and terminating in a backwardly extending portion11. I

The backwardly extending portion 11 communicates with the sinuous coils18, which extend downward on the left side 48 of the evaporator, acrossthe bottom of the frozen food compartment I5, and sinuously back andforth until compartment and the entire left side of the evaporator aresubstantially covered with coils. Thereafter the coils extend upward at"and across the left side of the evaporator wall ad- 'jacent the top at88 and communicate with the receiver 69 at the portion 85. i

Various ways of arranging the coils sinuously on these parts may beemployed; but the coils are preferably arranged in such a'mannenthat theice cream compartment is cooled first, theice freezing shelf is coolednext, and the rest of the evaporator is cooled last. i

According to the present invention, the amount of refrigerant availableis carefully proportioned so that the ice cream compartment is alwaysthe left side and the bottom of the frozen food cooled to a suitabletemperature below freezing,

to high pressure liquid, purple lining to low pressure gas, and bluelining to low pressure liquid.

In the refrigeration system, I80 indicates the motor-compressor housing.which is of the sealed type, having an oil sump IOI and an upper motorchamber I02. The compressor is located in the signal" and has its inletat M and its outlet a From the compressor outlet its a refrigerant tubeIll extends to a condenser section I01, which may include one or two ormore sinuous coils for pro-cooling the refrigerant immediately upon itsdischarge from the compressor. From the precooling coils I81 of thecondenser I88, a conduit I89 extends backto the inlet H0 of thecompressor motor housing I02.

The high pressure gas enters this housing I02 and is discharged from thetop of the housing at III, the entrained oil H2 dropping to the oil sumpIll.

From the outlet I ll of the motor housing I92 a conduit Ill extends tothe main condenser coils III, which are also arranged sinuously; and allforward and top edges are folded backward and outward, as indicated at84, to provide a smooth blunt edge. The back wall is terminated at 85with a backwardly extending flange 86 slightly above the shelf 81, andserves as a stop for engaging the ice trays, but permits the circulationof air into the ice tray space.

The inlet for refrigerant from the capillary tube 68 is at the rightrear of the shelf, from which the tube extends forwardly at 88, andthereafter sinuously from left to right on the bottom of the shelf, asindicated at 89. The tube emerges through a hole in the back wall at 90and thereafter extends downwardly on the right wall at 9|, across'thebottom wall. at 92, up the left side wall at 93, across the left sidewall adjacent the top at 94, downwardly on the left side wall at 95.-

Thereafter the tube is arranged sinuously back.

and forth across the bottom and up both side walls, as indicated at 96.On the left side wall the bends are located adjacent the shelf level;and on the right side wall the bends are located below the shelf inorder to permit the sinuous portions 96 to communicate with the sinuousportion 91, which leads to the forward end of the receiver 60a. Theopposite end of the receiver has the same suction pipe 64, which turnsupwardly into the receiver 69a.

Thus the shelf of this evaporator is cooled first with availablerefrigerant, and thereafter the remaining refrigerant is available forcooling the side walls and bottom of the evaporator.

Referring to Fig. 5, this is a schematic diagram of the refrigerationsystem, showing the various portions of the system and the condition ofthe refrigeration system at low ambient temperature. The parts of thedrawing are lined to illustrate by color the condition of therefrigerant; and the ac-' companying color code is located below thefigure. The color code corresponds to that employed in the Patent OfliceRules relating to trade-mark drawings; and as indicated, yellow liningin the code corresponds to high pressure gas. red lining .of the coilsI01 and I ll of the condenser are in heat conducting contact with amultiplicity of thin sheet metal fins H5.

The pre-cooling section I01 of the condenser has its coils preferablyarranged above the main condenser coils H4, receiving the hotter air,which has already passed the main condenser coil, but which is stillable to cool the pre-cooler section III! because of the highertemperature of the refrigerant in the precooler section.

From the outlet H6 of the main condenser section, a conduit extends to arefrigerant drier ll'l, consisting of a tubular metal member, and havinga pair of screens H8 located near its reduced ends, and having a dryingpowdered chemical, such as silica gel, arranged between the screens toabsorb waterj or water vapor which may be present in the refrigerant.

A capillary tube H9 extends from the opposite end of the drier and islocated in heat conducting contact at I20 with the suction tube I21,which extends from the accumulator I22 to the comprssor inlet I94. Thecapillary tube I20 acts as ..-:ja,;restrictor and heat exchanger and issoldered the suction tube over the major available The capillary tubecommunicates with the inlet to the evaporator at 68 and carries therefrigerant to the sinuous coils 10-12, which are located on the top,sides, and bottom of the ice cream compartment in the case of Fig. 3, orthe shelf coils 89 of Fig. 4.

From the ice cream compartment coils I2 a conduit 13 extends to thesinuous coils 16 on the shelf, and thence to the sinuous coils 18, whichare located on the outside of the body of the evaporator on the bottomand side wall.

The coils I8 communicate at 65 with the accumulator I22, which isequivalent to that illustrated at 60 and 69a in Figs. 3 and 4. Thesuction line I leads from the accumulator I22 to the compressor inletI04, as previously stated. The sizes of the conduits illustrated are, ofcourse, proportionate for the purpose for which they are employed; andall of the respective conduits are welded or brazed to each other andlocated suitably in the cabinet or on the outside thereof, as the casemay be with the condenser.

The present system is. applicable both to high aeeaeee side and low sidecompressor units; but is of the most importance in the high sidecompressor units because oil absorption of refrigerant increases greatlywith increased pressure and with drop in temperature. A high sidecompressor unit has been selected to illustrate the invention becausethe effects of oil absorption are most advantageous and pronounced insuch a unit.

The amount of refrigerant charge and amount of lubricant areproportioned so that the refrigeration system operates as follows: Theoil sump is provided with a supply of mineral oil; which substantiallyfills it, submerging the compressor; and the charge is sufficient sothat under high room temperature, with the compressor running, theevaporator is uniformly refrigerated because there is sufficient liquidrefrigerant distributed throughout the evaporator. The ice creamcompartment is generally cooled by liquid refrigerant, which maintainsthe same low temperature as long as there is liquid refrigerant in thecoils; but the rest of the evaporator may-be cooled by gas, which mayb'eat a higher temperature.

Refrigerant is absorbed by the mineral oil in the oil sump fill in anamount which depends upon the room temperature and the pressure of therefrigerant in the shell above the oil. Under room temperatures there isless refrigerant in the mineral oil; but under low room temperatureconditions there is quite a high percentage of refrigerant absorbed bythe mineral oil.

Thus, when the unit is operating under a low temperature ambient, thecooling effect of the body of the evaporator is proportionallydiminished and the food storage zone is not cooled to freezing, but ismaintained at a suitable temperature for preserving the food atabove-freezing temperatures.

The present system and structure accomplishes the provision of lowtemperature frozen food storage without excessive refrigeration in themain body of the cabinet; and this is accomplished with a minimum amountof outside baffling or extra controls. The motor compressor iscontrolled by a single thermostatic switch, which has its bulb attachedto the side of the evaporator, preferably adjacent the shelf, which isalso a part of the ice cream compartment.

The present system is not limited to any particular volume or size ofthe spaces for gas and oil, but depends upon the proper proportion ofthese volumes and the proper proportion of refrigerant charge and oilcharge.

For example, the volumes involved in the present system may beapproximately as follows in one size of refrigerator:

Gas volume in compressor 1230 051 volume in compressor 400 Condenservolume 260 Evaporator volumes, shelf tubing or ice cream compartmentonly 52 Remainder of evaporator tubing 118 Header or receiver volume 145per square inch, while the temperature of the motor compressor housingwas 206 degrees F.

Under these conditions it was calculated that there were 2 ounces of F12("Freon) in the mineral oil; 3.5 ounces of refrigerant vapor in themotor compressor housing and condenser: 4 ounces of refrigerant in thefreezing shelf tubes or ice cream compartment tubes; 2.5 ounces ofrefrigerant in the rest of theevaporator tubing; and 6 ounces ofrefrigerant in the header or receiver of the evaporator.

Thus, at an extremely warm ambient or room temperature, there isrelatively little refrigerant absorbed in the oil; and the entireevaporator is uniformly refrigerated.

At degrees F., ambient or room temperature, with the cold controlthermostat adjusted to its warmest position at the cut-in of thethermostat, the suction pressure was 28 pounds per square inch, whilethe head pressure was 73 pounds per square inch; and the temperature ofthe motor compressor housing was degrees F.

Under these conditions, it was calculated that there were seven ouncesof refrigerant absorbed in the oil, 2 ounces of refrigerant in the motorcompressor housing and condenser combined, 3 ounces of refrigerant inthe freezing shelf or ice cream compartment tubing, and 6 ounces ofrefrigerant in the header. The total refrigerant charge being about 18ounces, the exterior evaporator tubing which cools the food storagespace was substantially dry.

It will be noted that a much larger proportion of the refrigerant isabsorbed in the oil in the cooler 70 degree F. room as compared with thedegree F. room. .The absorbed refrigerant has increased from 2 to 7ounces. The most important point is that the freezing part of theevaporator is still supplied with refrigerant, while the external partof the evaporator, which cools the food storage space, is starved as torefrigerant.

When the door is closed and there is no special increased load, and theroom ambient is low, the running time of the motor compressor is shortand the oil is cold, the Freon absorption by the oil is great; and theevaporator has a minimum area refrigerated, which, however, issufficient to maintain the freezing compartment or ice cream compartmentat a considerably below-freezing temperature, while the rest of theevaporator is starved, but is still sufficiently cool to keep the foodstorage space at a proper higher tempera ture.

Whenever there is a higher ambient or the door is open or opened often,or there is an ice load or a greater food load, or an increased load forany reason, the running time of the compressor is increased; and thisincreases the amount of the evaporator which is refrigerated by liquidrefrigerant, and brings about more cooling, which is then required inthe food storage space.

Under low room temperature conditions a high percentage of therefrigerant is absorbed by the mineral oil; and the unit starts up withthe freezing tubes of the evaporator partly dry andthe remainder of theevaporator tubes, which cool the food storage space, relatively dry.

The freezing part of the evaporator may be kept constantly belowfreezing without overcooling the temperature in the food storage spaceof the cabinet; but the cooling effect in the food storage space issuitably increased also during high temperature ambient conditions.

It should be noted that it is only the food storage zone 22 in thecabinet that is maintained at above-freezing temperature. while theouter evaporator housing coils I6 or 95 which coolthis zone aremaintained at below-freezing temperature. All parts of the coolingevaporator are preferably maintained at a below-freezing temperature toavoid dripping or formation of ice, as distinguished from frost.

Under high room temperature conditions, less refrigerant is absorbed bythe oil, thus liberating the refrigerant for use in cooling the foodstorage space, in addition to maintaining the freezing portion of theevaporator at a considerably belowfreezing temperature.

It will thus be observed that I have invented an improved refrigerationsystem and refrigerator structure, in which the difficult condition ofproducing low temperatures for the storage of frozen food withoutover-cooling the rest of the cabinet has been satisfactorily net. Theabsorption of the refrigerant by the mineral oil in the motor compressorsump and elsewhere in the system automatically liberates enoughrefrigerant to cool the food storage space satisfactorily, both underhigh temperature ambient and low temperature ambient, without anycomplicated controls and with a minimum amount of baiiiing,

such as that represented by a molded plastic drawer located beneath theevaporator.

The only control required to accomplish this result is a singlethermostatic switch having a bulb located close to the freezing shelf orto the ice cream compartment coils.

'While I have illustrated a preferred embodiment of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but desire to avail myself of all changes withinthe scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States, is:

1. A refrigerating system comprising a substantially U-shaped sheetmetal evaporator having a transversely extending shelf of sheet metalprovided with depending attaching flanges secured to the side walls ofsaid evaporator, and having a rear wall substantially closing the spacebelow said shelf at the rear and projecting above said shelfsufiiciently to form a stop for ice trays,

said evaporator having one of its walls formed with an elongated ovalaperture having parallel sides and a substantially cylindrical receiverlocated in said aperture, and having flanges secured to the side wallabove and below said aperture, and cooling conduits comprising tubingsinuously arranged on the lower side of said I shelf and securedthereto, and extending from side to side to cover the shelf from rear tofront, said conduit thereafter extending to the rear on said shelf andemerging from the evaporator and extending sinuously from the left tothe right and upwardly on both-sides of the exterior of said evaporatorto cover said evaporator from the front to the rear and thereaftercommunicating with one end of said receiver, the other end of saidreceiver being provided with a suction tube connected to the inlet of arefrigerant condensing unit, and a restrictor connected to the outlet ofsaid unit and to the inlet of said evaporator, the said evaporator beingsupplied with refrigerant in an amount sufficient to cool said shelfunder all conditions to a below-freezing temperature, and the remainingrefrigerant in the 10 v system being sufficient so thatrefrigerantaccumulates in the receiver but the exterior coils on said evaporatorare substantially dry of refrigerant at the beginning of the cycle ofsupplying refrigerant to said evaporator.

2. A refrigerator cabinet comprising a sheet metal shell and a sheetmetal liner carried thereby and spaced therefrom, and provided withinsulation between the said shell and liner, the shell and linerextending substantially from the bottom of the cabinet to the top andbeing faced about a door opening by breaker strips, a substantially U-shaped evaporator'located in the upper part of said cabinet and carriedby the top of the liner and .the rear wall of the liner, said evaporatorhaving a transversely extending shelf spaced from its upper edgessufliciently to receive ice cube trays, molded plastic sliding guidescarried by the side walls of said liner below said evaporator. and amolded plastic insulating drawer slidably mounted in said guides belowsaid evaporator but permitting air circulation past said drawer at thefront and at the back of said drawer, a motor compressor carried by saidcab-.

inet and a condenser carried by the rear of said cabinet, said motorcompressor including a mineral oil sump with a charge of mineral oiladapted to absorb refrigerant in varying amounts, depending upon thetemperature of the oil, and a charge of refrigerant in the system whichis sufficient to supply the shelf with refrigerant during everyoperation of the motor compressor, the

refrigerant going first to the shelf coils and thereafter to coils onthe, sides and bottom of said evaporator which cool the remainder of thecabinet and the absorption of refrigerant in the mineral oil increasingas the ambient temperature surrounding said cab net drops so that as theambient t m erature decreases, the coi s on the exterior of said evaorator receive a diminishing amount of refrigerant, and the food storagespace exterior to said evaporator in said cabinet is aintain d at aconstantly suitable above freezin tem erature. I

3. A re ri erator cabinet comprising a sheet metal shell and a sheetmetal liner carried thereby and s a ed therefrom, and provided with insuation between the said she l and liner, the shell and liner exten ingsubstantially from the bottom of the cabinet to the top and being facedabout a door opening by breaker strips. a substantially U-shapedevaporator located in the upper part of said cabinet and carried by thetop of the liner and the rear wall of the liner, said evaporator havinga transversely extending shelf spaced from its upper edges sufficientlyto receive ice cube trays, molded plastic sliding guides carried by theside walls of said liner below said evaporator and a molded plasticinsulating drawer slidably mounted in said guides below said evaporatorbut permitting air circulation past said drawer at the front and at theback of said drawer, a.

motor compressor carried by said cabinet and a condenser carried by therear of said cabinet, said motor compressor including a mineral oil sumpwith a charge of mineral oil adapted to absorb refrigerant in varyingamounts, depending upon the temperature of the oil, and acharge ofrefrigerant in the system which is sufllcient to supply the shelf withrefrigerant during every operation of the motor compressor, therefrigerant going first to the shelf coils and thereafter to coils onthe sides and bottom of said evaporator which cool the remainder of thecabinet and the aeeacco absorption of refrigerant in the mineral oilincreasing as the ambient temperature surrounding said cabinet drops sothat as the ambient temperature decreases, the.coils on the exterior ofsaid evaporator receive a diminishing amount of refrigerant, and thefood storage space exterior to said evaporator in said cabinet ismaintained at a constantly suitable above-freezing temperature, the saidguides being provided with hearing apertures and an evaporator door ofmolded plastic having laterally proiecting trunnions in said aperturesand movable from a closed position in front of said evaporator to afully open position depending from said bearings. I

4. A refrigerator cabinet comprising a sheet metal shell and a sheetmetal liner carried thereby and spaced therefrom, and provided withinsulation between the said shell and liner, the shell and linerextending substantially from the bottom of ,the cabinet to the top andbeing faced about a door opening by breaker strips. a substantiallyU-shaped evaporator located in the upper part of said cabinet andcarried by the top of the liner and the rear wall of the liner, saidevaporator having a transverse y extending shelf spaced from its upperedges sufficiently to receive ice cube trays, molded plastic slidingguides carried by the side walls of said liner below said eva orator anda molded plastic insulating drawer slidably mounted in said guides belowsaid evaporator but permitting air circulation past said drawer at thefront and at the back of said drawer. a motor compressor carried by saidcabinet and a condenser carried by the rear of said cabinet, said motorcompressor including a mineral oil sump with a charge of mineral oil adated to absorb refrigerant in varying amounts, depending upon thetemperature of the oil. and a charge of refrigerant in the system whichis sufficient to supply the shelf with refrigerant d rin every o erationof the motor compressor. the refrigerant going first to the shelf coilsand, thereafter to coils on the sides and bottom of said evaporatorwhich cool the remainder of the cabinet and the absorption ofrefrigerant in the mineral oil increasing as the ambient temperaturesurrounding said cabinet dro s so that as the ambient temperaturedecreases, the coils on the exterior of said evapo ator receive adiminishing amount of refrigerant, and the food storage space exteriorto said evaporator in said cabinet is maintained at a constantlysuitable above-freezing temperature, the said cabinet being provided atits lowermost end with a slidably mounted vegetable drawer mounted inguides, and the said guides supporting a transparent cover, the air alsocirculating in front of and in back of said covering about said latterdrawer.

5. A refrigeration system comprising an insulated cabinet having abelow-freezing zone cooled by first below-freezing coils and a foodstorage zone cooled by second coils communicatlng without restrictionwith said first coils in series, to cool said second coils only withrefrigerant from said first coils, a motor compressor comprising amotor, a compressor and a housing enclosing the motor and compressor, acondenser and a restrictor connected in this order to said first coils,said second coils communicating with the suction inlet of saidcompressor-and said compressor having an oil sump, a charge of oil insaid sump and a charge of refrigerant of a type miscible with andabsorbed by said oil in said system,

. l2 portion being absorbed at lower ambient temperatures, and a lesserportion absorbed at higher ambient temperatures, the volumes of saidcoils, said oil charge and said refrigerant charge being proportioned sothat the amount of refrigerant not absorbed and available for coolingsaid first coils is sufficient to maintain a below-freezing tempera-'ture in the below-freezing zone at the highest ama portion of saidrefrigerant being absorbed in bient contemplated, and the amount ofrefrigerant available for said second coils is sufficient for coolingthe food storage zone at a suitable abovefreezing temperature atordinary ambients, and is suflicient for increasing proportionately thecooling effect of said second coils at higher ambients due to therelease-of absorbed refrigerant from the oil at higher ambients, butdecreasing the cooling effect of said second coils proportionately atlower ambients, due to greater absorption of refrigerant at the lowerambients, to avoid overcooling or undercooling the food storage spacewhile maintaining below-freezing temperatures in the freezing zone.

6. A refrigeration system comprising an insulated cabinet having abelow-freezing zone cooled by first below-freezing coils and a foodstorage zone cooled by second coils communicating without restrictionwith said first coils in series, to cool said second coils only withrefrigerant from said first coils, a motor compressor comprising amotor, a compressor and a housing enclosing the motor and compressor, acondenser and a restrictor connected in this order to said first coils,said second coils communicating with the suction inlet of saidcompressor and said compressor having an oil sump, a charge of oil insaid sump and a charge of refrigerant of a type miscible with andabsorbed by said oil in said system, a portion of said refrigerant beingabsorbed in said oil at ordinary ambient temperatures, a larger portionbeing absorbed at lower ambient temperatures, and a lesser portionabsorbed at higher ambient temperatures, the volumes of said coils, saidoil charge and said refrigerant charge being proportioned so that theamount of refrigerant not absorbed and available for cooling said firstcoils is suflicient to maintain a below-freezing temperature in thebelow-freezing zone at the highest ambient contemplated, and the amountof refrigerant available for said second coils is sufiicient for coolingthe food storage zone at a suitable above-freezing temperature atordinary ambients, and is sufficient for increasing proportionately thecooling effect of said second coils at higher ambients due to therelease of absorbed refrigerant from the oil at higher ambients, butdecreasing the cooling effect of said second coils proportionately atlower ambients, due to greater absorption of refrigerant at the lowerambients, to avoid overcooiing or undereooling the food storage spacewhile maintaining below-freezing temperatures in the freezing zone, saidsystem having a receiver interposed in the conduits from said secondcoils to said compressor inlet, said receiver storing a predeterminedamount of refrigerant immediately available to the compressor at thebeginning of the compressor operation to supply refrigerant quickly tothe first coils.

7. A refrigeration system comprising an insulated cabinet having abelow-freezing zone cooled by first below-freezing coils and a foodstorage zone cooled by second coils communicating without restrictionwith said first coils in series, to cool said second coils only withrefrigerant from said first coils, a motor compressor comprising amotor, a compressor and a housing enclosing the motor and compressor, acondenser and a restrictor connected in this order to said first coils,said second coils communicating with the suction inlet of saidcompressor and said compressor having an oil sump, a charge of oil insaid sump and a charge of refrigerant of a type miscible with andabsorbed by said oil in said system, a portion of said refrigerant beingabsorbed in said oil at ordinary ambient temperatures, a larger portionbeing absorbed at lower ambient temperatures, and a lesser portionabsorbed at higher ambient temperatures, the volumes of said coils. saidoil charge and said refrigerant charge being proportioned so that theamount of refrigerant not absorbed and available for cooling said firstcoils is sufficient to maintain a, below-freezing.

temperature in the below-freezing zone at the highest ambientcontemplated, and the amount of refrigerant available for said secondcoils is suflicient for cooling the food storage zone at a suitableabove-freezing temperature at ordinary ambients, and is sufficient forincreasing proportionately the cooling effect of said second coils athigher ambients due to the release of absorbed refrigerant from the oilat higher ambients, but decreasing the cooling effect of said secondcoils proportionately at lower ambients, due to greater absorption ofrefrigerant at the lower ambients, to avoid overcooling or undercoolingthe food storage space while maintaining below-freezing temperatures inthe freezing zone, said condenser including main condenser coils andpreliminary cooling coils, the latter coils being connected directly tothe compressor outlet and to the top of the motor housing, to removeheated refrigerant immediately from the compressor, to cool andpartially condense it and to cool the motor by revaporization as therefrigerant runs down in the motor housing with the oil separating intothe sump, said main condenser coils being connected to the top of themotor compressor.

8. A refrigeration system comprising an insulated cabinet having abelow-freezingzone cooled by first below-freezing coils and a foodstorage zone cooled by second coils communicating without restrictionwith said first coils in series, to

cool said second coils only with refrigerant from said first coils, amotor compressor comprising a motor, a compressor and a housingenclosing the motor and compressor, a condenser and a restrictorconnected in this order to said first coils, said second coilscommunicating with the suction inlet of said compressor and saidcompressor having an oil sump, a charge of oil in said sump and a chargeof refrigerant of a type miscible with and absorbed by said oil in saidsystem, a portion of said refrigerant being absorbed in said oil atordinary ambient temperatures, a larger portion being absorbed at lowerambient temperatures, and a lesser portion absorbed at higher ambienttemperatures, the volumes of said coils, said oil charge and saidrefrigerant charge being proportioned so that the amount of refrigerantnot absorbed and available for cooling said first coils is sufficient tomaintain a below-freezing temperature in the below-freezing zone at thehighest ambient contemplated, and the amount of refrigerant availablefor said second coils is sufficient for cooling the food storage zone ata suitable above-freezing temperature at ordinary ambients, and issufficient for increasing proportionately the cooling effect of saidsecond coils at higher ambients due to the release of absorbedrefrigerant from the oil at higher ambients, but decreasing the coolingeffect of said second coils proportionately at lower ambients, due togreater absorption of refrigerant at the lower ambients, to avoidovercooling or undercoolingthe food storage space while maintainingbelow-freezing temperatures in the freezing zone, the said coils beingcarried by upper and lower sheet metal evaporator parts, providingextended heat absorbing surfaces in said zones, in heat conductingrelation with said coils.

9. In a refrigeration system, the combination of a motor compressorhaving an oil sump and a motor housing, the compressor being located insaid sump and having a suction inlet and a pressure outlet, apreliminary cooling condenser communicating directly with saidcompressor outlet, said preliminary condenser communicating with themotor housing to partially condense refrigerant and cool the motor partstherewith, said housing having an upper outlet, a main condensercommunicating with said upper outlet, a restrictor leading from saidmain condenser to an evaporator, said evaporator having a pair of coilsections in series with each other and in unrestricted communicationwith each other, the first section'of coils cooling a first zone and thesecond section of coils cooling a second zone, a charge of refrigerantin said system and a charge of oil in said sump, a suction tube leadingfrom the second evaporator coils to the inlet of said compressor,constituting a closed system, the volume of' the spaces in saidevaporator coils, said motor housin said condensers and communicatingconduits being proportioned relative to the charge of refrigerant andthe amount of mineral oil charge in said sump, the first evaporatorcoils being supplied with refrigerant first for cooling saidbelow-freezing zone, and the second coils of said evaporator beingsupplied with such refrigerant as is available after passing throu hsaid first coils, to be used in the second coils for cooling anabove-freezing zone, the amount of refrigerant absorbed by the oilincreasing as the ambient temperature drops so that the second coils arestarved for refrigerant at low ambient temperatures to preventovercooling of the above-freezing zone, the refrigerant being releasedfrom the oil as the ambient temperature increases to increase the amountof refrigerant available for the second coils to re ulate automaticallvthe amount of cooling provided by the second coils for the above-freezinzonewhile maintaining below-freezing temperatures in the first zone atall times by means of said first coils.

10. In a refrigeration system, the combination of a motor compressorhaving an oil sump and a motor housing, the compressor being located insaid sump and having a suction inlet and a pressure outlet, apreliminary cooling condenser communicating dire tlv with saidcompressor outlet, said preliminary condenser communicatin with themotor housing to partiallv condense refrigerant and coolthe motor partstherewith,

said housing havin an upper outlet, 2. main condenser communicating withsaid upper outlet, a rectrictor leading from said main condenser to anevaporator, said evaporator having'a pair of coil sections in serieswith each other and in unrestricted communication with each other, thefirst section of coils cooling a first zone and the second section ofcoils cooling a second zone, a charge of refrigerant in saidsystem and acharge of oil in said sump, a suction tube leading from the secondevaporator coils to the inlet of said compressor, constituting a closedsystem, the

wolume of the spaces in said evaporator coils, said motor housing, saidcondensers and communicating conduits being proportioned relative to thecharge of refrigerant and the amount of mineral oil charge in said sump,the first evaporator coils being supplied with refrigerant first forcooling said below-freezing zone, and the second coils of saidevaporator being supplied with such refrigerant as is available afterpassing through said first coils, to be used in the second coils forcooling an above-freezing zone, the amount of refrigerant absorbed bythe oil increasing as the ambient temperature drops so that the secondcoils are starved for refrigerant at low ambient temperatures to preventovercooling of the above-freezing zone, the refrigerant being releasedfrom the oil as the ambient temperature increases to increase the amountof refrigerant available for the second coils to regulate automaticallythe amount of cooling provided by the second coils for theabove-freezing zone while maintaining below-freezing temperatures in thefirst zone at all times by means of said first coils, the first coilscomprising coils located on an inner partition of the evaporator whichhas an outer U-shaped housing and the said second coils being located onsaid outer housing.

. 11. In a refrigeration system. the combination of a motor compressorhaving an oil sump and a motor housing, the compressor being located insaid sump and having a suction inlet and a pressure outlet, apreliminary cooling condenser communicating directly with saidcompressor outlet, said preliminary condenser communicating with themotor housing to partially condense refrigerant and cool the motor partstherewith, said housing having an upper outlet, a main condensercommunicating with said upper outlet, 9. restrictor leading from saidmain condenser to an evaporator, said evaporator having a pair of coilsections in series with each other and in unrestricted communicationwith each other, the first section of coils coolin a first zone and thesecond section of coils cooling a second zone, a

char e of refri erant in said system and a charge of oil in said sump asuction tube leading from the second evaporator coils to the inletof'said compressor, constituting a closed system, the volume of thespaces in said evaporator coils, said motor housin said condensers andcommunicating conduits being proportioned relative to the char e ofrefri erant and the amount of mineral oil char e in said sump, the firstevaporator coils being supplied with refrigerant first for cooling saidbelow-freezing zone, and the second coils of said evaporator beinsupplied with such refri erant as is available after passing throu hsaid first coils, to be used in the second coils for cooling anabove-freezin zone, the amount of refri erant absorbed by the oilincreasing as the ambient temperature drops so that the second coils arestarved for refrigerant at low ambient temperatures to preventovercooling of the above-freezing zone, the refri erant bein releasedfrom the oil as the ambient temperature increases to increase the amountof refrigerant available for the second coils to regulate automaticallythe amount of cooling provided bv the second coils for theabove-freezing zone while maintaining below-freezing temperatures in thefirst zone at all times by means of said first coils, the first coilscomprising coils located on an inner partition of the evaporator whichhas an outer U-shaped housing and the said second coils being located onsaid outer housing, the said evaporator also including a secondpartition defining a supercold department and having a third section ofevaporator coils located on the walls of said ,supercold department andconnected in the system to receive the refrigerant first.

12. In a refrigeration system, the combination of a motor compressorhaving an oil sump and a motor housing, the compressor being located insaid sump and having a suction inlet and a pressure outlet, a preliminarcooling condenser communicating directly with said compressor outlet,said preliminary condenser communicating with the motor housing topartially condense refrigerant and cool the motor parts therewith, saidhousing having an upper outlet, 9, main condenser communicating withsaid upper outlet, at restrictor leading from said main condenser to anevaporator, said evaporator having a pair of coil sections in serieswith each other and in unrestricted communication with each other, thefirst section of coils cooling a first zone and the second section ofcoils cooling a second zone, a charge of refrigerant in said system anda charge of oil in said sump, a suction tube leading from the secondevaporator coils to the inlet of said compressor, constituting a closedsystem, the volume of the spaces in said evaporator coils, said motorhousing, said condensers and communicating conduits being proportionedrelative to the charge of re frigerant and the amount of mineral oilcharge in said sump, thefirst evaporator coils being supplied withrefrigerant first for cooling said belowfreezing zone, and the secondcoils of said evaporator being supplied with such refrigerant as isavailable after passing through said first coils, to be used in thesecond coils for cooling an abovefreezing zone, the amount ofrefrigerant absorbed by the oil increasing as the ambient temperaturedrops so that the second coils are starved for refrigerant at lowambient temperatures to prevent overcooling of the above-freezing zone,the refrigerant being released from the oil as the ambient temperatureincreases to increase the amount of refrigerant available for the secondcoils to regulate automatically the amount of cooling provided by thesecond coils for the abovefreezmg zone while maintaining below-freezingtemperatures in the first zone at all times by means of said firstcoils, the said below-freezing zone being located inside a U-shapedevaporator having a partition provided with said first coils and thesaid above-freezing zone comprising an enclosure outside of saidevaporator cooled by said second coils located on the outside of saidU-shaped evaporator.

13. A refrigeration system comprising, an insulated cabinet having anouter shell and an inner liner separated by insulation and having a dooropening and an insulated door, a motor compressor including a motorhousing and a compressor located in an oil sump carried by the motorhousing, a preliminary condenser connected directly to the compressoroutlet and discharging into the top of the motor housins, a maincondenser connected to the top of the motor housing and a restrictorconnected to the outlet of said main condenser, an evaporator includingan outer sheet metal casing and an inner shelf, coils carried by theouter evaporator casing, coils carried by the shelf and a receivercarried by the upper part of said evaporator, said restrictor beingconnected to the shelf coils which are connected to the outer coils andthence to the receiver, a suction tube from the receiver to thecompressor inlet, and. supply of oil and a charge of refrigerant in saidsystem.

sumcient to cause below-freezing temperatures on said shell and to coolthe remainder of the cabinet at temperatures above-freezing by means ofsaid outer coils at ordinary ambient temperatures, the oil absorbingrefrigerant at lower ambients and. releasing refrigerant at higheramaeeapoo in the cabinet outside the evaporator while maintaining abelow-freezing zone inside the evaporator.

CARL F. ALSING.

References Cited in the tile 01 this patent UNITED STATES PATEN TSNumber bient temperatures to regulate automatically the 10 2,410,360

supply of refrigerant to the outer casing coils to maintain a constantaboye-treezing temperature Baler May 1, m1

